2511257561 has 4 divisors (see below), whose sum is σ = 2658978612. Its totient is φ = 2363536512.

The previous prime is 2511257557. The next prime is 2511257563. The reversal of 2511257561 is 1657521152.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1034008336 + 1477249225 = 32156^2 + 38435^2 .

It is a cyclic number.

It is not a de Polignac number, because 2511257561 - 2² = 2511257557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2511257563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73860500 + ... + 73860533.

It is an arithmetic number, because the mean of its divisors is an integer number (664744653).

Almost surely, 2^2511257561 is an apocalyptic number.

It is an amenable number.

2511257561 is a deficient number, since it is larger than the sum of its proper divisors (147721051).

2511257561 is a wasteful number, since it uses less digits than its factorization.

2511257561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147721050.

The product of its digits is 21000, while the sum is 35.

The square root of 2511257561 is about 50112.4491618600. The cubic root of 2511257561 is about 1359.2429395582.

The spelling of 2511257561 in words is "two billion, five hundred eleven million, two hundred fifty-seven thousand, five hundred sixty-one".